Process for the preparation of pyrocatechin aldehyde



' No Drawing.

tain new and useful Improvements in esses for the Preparation ofPyrocatechin 20 the action of linol/of gaseous "converted completely andwithout 26 is split oif,t usg UNITED STATES rATENT OFFICE.

'Lunwre seminar, on

I RQCESS FOR THE PREPARATION MUNICH, GERMANY. I

or PYROCATECHIN ALnEnYnE.

To all whom it maycoacem: f Be it known that I, Dr. LUDWIG SoHMIp'r,

subjectof the .Emperor of Germany,- residing at Munich, Germany, haveinvented cer- Proc- Aldehyde,'of which the following isa specification.f

' If piperonal is treated with thionylchlorid at the temperatureof thewater bath, a reaction takes-place according to the equation:

aonoisooi non-cl -so,

- Piperonaldichlorid (piperonylchlorid) of a fusing point of 59 0.

being formed besides (see Ber. Deutsche Chem. 1917 and J own. hem.

freesulfuroiis acid Gas. vol. '41 page Soc. vol. 93 (I) page 572).

I have found that pip'eronaldichlorid by I chlorin is formation ofby-products into dichlorpiperonylchlorid, a substitution of the twomethyl hydrogen atoms takin place, while hydrochloric acid o I D e.

30 The saponification of the dichlorpiperonylchlorid with water yieldspyrocatechinaldehyde, carbonic and hydrochloric acids being split ofi'uThe chlorination can be eifected with or without solvents, for instancewith benzene, s chloroform or carbon tetra of no material difference forthe formation of the final product whether the action of thionylchloridand gaseous chlorin on piper- 40 onal takes place successively orsimultaneously. The reaction proceeds very quickly ,into' actionsuccessively I can also effect the reaction with or with chlorid.Itisnalso g speclflcatlpnof Letters Patent? Patented Jan.6,1920.'Application flled liarch '31, 1917. Serial No. 159,035. I

Example;

, 15 kilo of piperonal are treated with 12 kilo -of thionylchlorid. Thesolution formed is heated on the water-bath, until the reac tion iscompleted. 14.2 kilo of gaseous chlorin, preferably taken from a steel'cylinder containing compressed chlorin, are passed into the solution,whereby the formation of dichlorpiperonylchlorid is effected. The

product of reaction is decomposed by water I sulfurous acid formed as aby-product does Y not interfere with the action of the chlorin on themethyl groupand it is immaterial whether thionylchlorid and chlorin gascome or simultaneously.

out solvents, for instance chloroform. WhatI claim is a 1. A process forthe preparation of pyrocatechin aldehyde consisting in treating p1p-'eronal with thionylchlorid and gaseous chlorin, and then saporiifyingthe dichlorpiperonylchlorid thus formed with water, essentially asdescribed. I

2. A process for the preparation of pyrocatechin aldehyde-consisting intreating piperonal with thionylchlorid and passing gaseous' chlorin intopo'nifyingthe dichlorpiperonylchlorid thus the solu ion, and thensaformed with water, essentially .as described.

In testimon whereof I aifix my signature in .presence'o two iwitnesses.

I DR. LUDWIG SCHMIDT. "Witnesses: r u 1 HERMANN 'ScHM'mT,

Novs'r SGHMIDT-

